ABSTRACT
We show that hybrid MnOx/C60 heterojunctions can be used to design a storage device for spin-polarized charge: a spin capacitor. Hybridization at the carbon-metal oxide interface leads to spin-polarized charge trapping after an applied voltage or photocurrent. Strong electronic structure changes, including a 1-eV energy shift and spin polarization in the C60 lowest unoccupied molecular orbital, are then revealed by x-ray absorption spectroscopy, in agreement with density functional theory simulations. Muon spin spectroscopy measurements give further independent evidence of local spin ordering and magnetic moments optically/electronically stored at the heterojunctions. These spin-polarized states dissipate when shorting the electrodes. The spin storage decay time is controlled by magnetic ordering at the interface, leading to coherence times of seconds to hours even at room temperature.
ABSTRACT
By means of scanning probe microscopy we demonstrate that Au(+) on NaCl films adsorbs in an embedded, slightly off-centered Cl-Cl bridge position and can be switched between two equivalent mirror-symmetric configurations using the attractive force exerted by a scanning probe tip. Density functional theory calculations demonstrate that the displacement of the Au atom from the centered position of the bridge configuration is accompanied by a large lifting of the closest Cl atom leading to significant changes in the local electrostatic field. Our findings suggest that Au(+) can be used to toggle the local electrostatic field.
ABSTRACT
We show charge-state manipulation of single Au adatoms on 2-11 monolayer (ML) thick NaCl films on Cu surfaces by attaching or detaching single electrons via the tip of an atomic force microscope (AFM). Tristate charge control (neutral, negatively charged, and positively charged) is achieved. On Cu(100) and Cu(111) supports, charge tristability is achieved independently of the NaCl layer thickness. In contrast, on Cu(311), only Au anions are stable on the thinnest NaCl films, but neutral and positive charge states become sufficiently long lived on films thicker than 4 ML to allow AFM-based charge-state-manipulation experiments.
